Automation technology routinely uses field devices for monitoring, registering and controlling process parameters within the automation environment/industrial environment. Exemplary field devices may operate as sensors, for example, fill level measuring devices, mass flow measuring devices, pressure- and temperature-measuring devices, pH- and redox-potential-measuring devices, conductivity measuring devices, etc. for process automation technology. Such devices operate as sensors that detect and report on the corresponding environment parameters such as, fill level, flow, e.g. flow rate, pressure, temperature, pH-value and conductivity value, respectively. Other types of field devices may operate as actuators that enable control of process parameters, e.g. valves, which control flow of a liquid in a section of pipeline, or pumps, which change fill level in a container etc.
Field devices are typically communicatively coupled with application programs that can be used for process control, process visualization, device-management (configuration and servicing) and for plant management (asset management). The communicative coupling may be achieved by communication systems or protocols such as PRO FIBUS®, FOUNDATION-FIELDBUS®, HART®, etc.
The integration of field devices into application programs occurs through defined device descriptions that are provided by device manufacturers, so that the application programs as well as other devices communicating with field devices can recognize and interpret the meaning of data supplied by the field devices.
A specific type of device description is the Device Type Manager (DTM) description, which corresponds to Field Device Tool (FDT) specifications. The FDT specifications, serving as an industry standard, have been developed by the PNO (Profibus Nutzer Organisation (Profibus User Organization)) in cooperation with ZVEI (Zentralverband Elektrotechnik-und Elektroindustrie).
Field device manufacturers develop and distribute DTMs for their field devices based on defined device descriptions such as the FDT specification—which DTMs encapsulate all variables and functions of the pertinent field device and offer, most often, a graphical user interface for servicing the devices.
The DTMs require an FDT compatible frame application (FDT frame application)—which enable an operator to monitor and control the corresponding field device through an interface generated or controlled by the FDT frame application. The FDT frame application and the corresponding DTMs together enable access to field devices (e.g. to device parameters, measured values, diagnostic information, status information, etc.), as well as for invoking special functions, which individual DTMs make available.
DTMs typically correspond to one of two types of DTM—device DTMs for field devices, and communication DTMs for field communication control. In implementation, the DTMs are device objects, which, together with the FDT frame application, represent an object-oriented configuration system for field devices of automation technology.
Since FDT specifications are updated from time to time, later versions of FDT specifications offer operating capabilities for the FDT frame application that are not offered by or supported by earlier versions of the FDT specifications. For example, while the FDT specification version 1.2.x requires implementation through older technology (Microsoft COM) and can at most only use Microsoft .NET 3.5 software framework, the subsequent FDT specification versions 2.x use the Microsoft .NET 4.x software framework.
Additionally, even current versions of FDT specifications do not support rich content within the user interface display—for example through implementation of Hyper Text Markup Language (HTML) capabilities—as a result of which, such capabilities are not implemented within either current or earlier FDT frame applications There is accordingly a need for enabling existing FDT frame applications to implement user interface capabilities that may not be provided within the current or earlier FDT specifications.
Another consequence arising out of the changing capabilities of incrementally developed FDT specifications is that many automation environments already have FDT frame applications that are configured according to an earlier FDT specification—and such FDT frame applications are unable to benefit from the improved capabilities of the subsequently developed FDT specifications. Since replacement or upgrading the FDT frame application is a time and resource intensive procedure, entities are typically unwilling to make the change on a frequent basis—and as a result there is a need to ensure that FDT frame applications that have been developed based on an earlier FDT specification are able to implement the advanced capabilities of later FDT specifications.